Electrically-controlled soldering pot apparatus

ABSTRACT

An electrically-controlled soldering pot apparatus with a timer control mechanism and a temperature control mechanism; a method of alerting a user when to exchange a solder bath of the apparatus before erosion to the solder bath occurs; and a method of varying the heating rate applied to a variety of lead-free solders in a solder bath housed in the apparatus.

BACKGROUND OF THE INVENTION

Soldering baths are generally used for holding molten solder, which,once molten, may be applied to an electrical component substrate tocouple various electrical components to the same.Electrically-controlled soldering baths are known in the art. A typicalelectrically-controlled soldering bath may have, for example, a solderpot to hold molten solder, a heating mechanism to heat the solder, andan electrical control mechanism to control the supply of power to theheating mechanism. Typically, solder is composed of either a lead-basedalloy, such as lead-tin, or more recently, a lead-free metal alloy, suchas tin-copper, tin-silver, tin-silver-copper or tin-zinc. With increasedenvironmental concerns and regulations, lead-free solder is now broadlyused.

With the advent of lead-free solders, certain problems have arisen inrelation to certain components of soldering baths. For example, atypical problem associated with conventional soldering baths is theerosion of the soldering bath. A typical soldering bath is made ofstainless steel and tends to erode over time, especially if thesoldering bath houses lead-free solder, which tends to erode thesoldering bath faster than lead-based solders. The erosion of astainless steel soldering bath may leach impurities into the lead-freemolten solder, compromising the integrity of the molten solder.Moreover, the erosion of the soldering bath may create a safety hazardto the user since the structural integrity of the typical stainlesssteel soldering bath may be compromised by erosion. Furthermore, erosionmay breach the structural integrity of the soldering bath such thatmolten solder leaks from the soldering bath, which in turn may burn theoperating mechanism and create a fire risk. To address these problems,some manufacturers now manufacture soldering baths made of, for example,cast iron, titanium or stainless steel coated with nitrides. Althoughthese alternative soldering baths may be resistant to erosion for alonger period of time, they are still not ultimately protected fromerosion and will experience the same problems as discussed above whentheir lifetimes expire.

Another problem associated with conventional electrically-controlledsoldering baths relates to the time in which it takes to melt thevarious lead-free solders typically used, e.g., tin-copper, tin-silver,tin-silver-copper or tin-zinc. For example, the melting point oftin-copper(0.7%) is 227 degrees Celsius, tin-silver(3.5%) is 216 degreesCelsius, and tin-silver(3.5%)-copper(0.7%) is 217 degrees Celsius. In aconventional soldering bath, the heat applied to the soldering bath forany given lead-free solder is uniform and uncontrolled. Thus, thevarious lead-free solders are subjected to the same amount of heatwithout any regard to the individual melting points of various lead-freesolders. This may lead to overheating of a given lead-free solder or,alternatively, an unnecessary increase in time to melt the lead-freesolder.

Yet another problem is the heating mechanism associated with aconventional soldering pot apparatus. Typically, the heating mechanismis integrated or affixed directly onto or into a soldering bath inconventional soldering pot apparatuses. Because of the nature ofapplying solder in a soldering application, molten solder typically mayleak onto the soldering pot, and therefore the heating mechanism. Thus,when the need arises to exchange the soldering bath, the heatingmechanism may be permanently stuck to the soldering bath. Therefore, theentire soldering bath apparatus may need to be replaced once thelifetime of the soldering pot expires. Thus, improvements to theproblems discussed previously are desired.

SUMMARY OF THE INVENTION

The present invention relates to an electrically-controlled solderingpot apparatus with a timing control mechanism and a temperature controlmechanism; a method of alerting a user when to exchange a solder bathbefore solder leaking by erosion to the solder bath occurs in anelectrically-controlled soldering pot apparatus; a method of varying theheating rate applied to a variety of solders in a solder bath housed inan electrically-controlled soldering pot apparatus; and a method ofchanging solder baths.

The soldering pot apparatus comprises a heater assembly releasablycoupled to a cup-shaped solder bath with a flange. A solder bath supportplaces the heater assembly in thermal contact with the solder bath,which is secured to the solder bath by a securing mechanism. Both thesolder bath and the heater assembly may be mounted or dismounted bymanipulation of the securing mechanism. The solder bath support isadapted to rest on a lower horizontal surface of the housing andposition the solder bath at a distance from the lower horizontalsurface. A tray is situated beneath the solder bath and secured by thesolder bath support. The tray is provided to collect solder which mayleak from a cracked solder bath positioned above it. A housing enclosesthe components and includes a face plate with user controls to select aplurality of control functions and an on/off switch. A power supply cordis attached to the housing to supply power to the soldering potapparatus.

To alert a user when to replace a given solder bath before it begins toleak solder by erosion, a timing control mechanism is provided. Userinteraction to set the timing control mechanism takes place at the usercontrols. The timing control mechanism is electrically coupled to apower supply, which in turn supplies power to the heater assembly, whichin turn provides heat to the soldering bath. Before operation, a usermay program the timing control mechanism to a preferred time value. Oncethe preferred time value is reached, the power provided to the heatingblocks by a set of heaters will automatically be terminated and an alarm(or other audio or visual indicator) will then sound, alerting the userthat the solder bath needs to be exchanged. If the soldering potapparatus is unplugged or switched off, the pre-set preferred time valueis retained by a memory circuit. The timing control mechanism is notlimited to alerting the user when to exchange the soldering bath, butmay also be programmed, for example, to shut down power to the heaterassembly in the event a user forgets to turn off the apparatus.

To decrease the time to melt lead-free solders, a temperature controlmechanism is provided. User interaction to set the temperature controlmechanism takes place at the user controls. The temperature controlmechanism comprises a plurality of user controls on the face of thesoldering pot apparatus housing, a heating mechanism and a sensor. Theuser controls may be programmed to a numerical value which correspondsto a conventional lead-free solder, such as tin-copper, tin-silver,tin-silver-copper or tin-zinc, which in turn corresponds to a preferredtemperature. Additionally, the user controls may be programmed to anumerical value which corresponds to a solder bath size, which in turncorresponds to a preferred temperature. Once a conventional lead-freesolder type and a solder bath size are programmed into the apparatus bythe user, full power from the power supply is applied to the heaterassembly until the preferred temperature as measured by the temperatureof a heating block is detected by the sensor. Once the preferredtemperature is reached as detected by the sensor, the temperature iscontrolled so that the lead-free solder remains in a molten state whilesimultaneously preventing the lead-free solder from overheating or frombecoming solid.

Other objects and advantages of the present invention will become moreapparent to those persons having ordinary skill in the art to which thepresent invention pertains from the foregoing description taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a soldering pot apparatus of the presentinvention.

FIG. 2 is an exploded perspective view of the soldering pot apparatus ofFIG. 1.

FIG. 3. is a perspective view of a heater assembly of the soldering potapparatus of FIG. 2.

FIG. 4 illustrates the exchanging of a first solder bath for a secondsolder bath of the soldering pot apparatus of FIG. 1.

FIG. 5 is a simplified cross-sectional view of the soldering potapparatus of FIG. 1 illustrating securing means for securing the heaterassembly of FIG. 3 to a solder bath.

FIG. 6 is a simplified cross-sectional view of the soldering potapparatus of FIG. 1 illustrating a first alternative securing means forsecuring the heater assembly of FIG. 3 to a solder bath.

FIG. 7 is a perspective view of a second alternative securing means forsecuring the heater assembly of FIG. 3 to a solder bath.

FIG. 8 is a simplified cross-sectional view of the soldering potapparatus of FIG. 1 illustrating a third alternative securing means forsecuring the heater assembly of FIG. 3 to a solder bath.

FIG. 9 a is a simplified cross-sectional view of the soldering potapparatus of FIG. 1 illustrating the heater assembly of FIG. 3 in anopen position.

FIG. 9 b is a cross-sectional view of the soldering pot apparatus ofFIG. 1 illustrating the heater assembly of FIG. 3 in a closed position.

FIG. 10 is a wiring diagram of the soldering pot apparatus of FIG. 1.

FIG. 11 is a block diagram of the schematics of the soldering potapparatus of FIG. 1.

FIG. 12 is a graph showing temperature-time curves and illustrating thetime necessary to reach a target temperature for lead-free solderswithout pre-selecting a value corresponding to a type of solder.

FIG. 13 is a graph showing temperature-time curves and illustrating thetime necessary to reach a target temperature for lead-free solders withpre-selecting a value corresponding to a type of solder.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 illustrates an embodiment of a soldering pot apparatus generallyat 100 of the present invention. In this embodiment, a solder bath 106is depicted with a flange 108 substantially encompassed by a housing102. The housing 102 is approximately three-dimensional rectangularshaped and has dimensions of approximately 8.7 inches in length, 5.7inches in width and 3.2 inches in depth. The housing 102 may becomprised of a plurality of metal plates secured together by screws,welding, or other securing means to form the substantially rectangularshape, as can be understood from FIG. 2. The housing 102 also includes aface plate 128 with an ON/OFF switch 130, a plurality of programmablebuttons 132 and a display 134. Secured to an upper horizontal surface136 of the housing 102 is an overflow tray 104. The flange 108 of thesolder bath 106 is positioned such that any molten solder which mayoverflow or leak from the solder bath 106 when it is holding moltensolder will spill onto the overflow tray 104, thereby protecting theother components of the soldering pot apparatus 100, including thehousing itself, from damage caused by molten solder.

Also shown in FIG. 1 is a power cord 122 through which power is suppliedto the soldering pot apparatus 100. Additionally, various accessoriesused in soldering applications are illustrated, such as a wastecollector 124, a spatula 126 and a hex wrench 127 for manipulating thescrews 120 that hold the heater assembly 144 (not shown in this figure)adjacent to the solder bath 106 (explained more fully below).Advantageously, the waste collector 124 may be attached to a pluralityof different sides of the housing 102 depending on the user'spreference. The waste collector 124 and spatula 126 may be made ofstainless steel, titanium, cast iron or similar heat-resistant material.

In FIG. 2, an exploded view of the soldering pot apparatus 100 isillustrated. In this view, internal components of the solder potapparatus 100 and their relationship to each other are more clearlyshown. For example, the heater assembly 144 is shown in relation to asolder bath support 142, which is shown in relation to a drip tray 140and a heat insulator 138. As explained more fully below, the solder bathsupport 142 supports the solder bath 106 by horizontal protrusions 123and 129 while simultaneously supporting the heater assembly 144 by afirst and second set of flanges 133 and 135 (see FIG. 5) in a positionadjacent to the solder bath 106. Moreover, a drip tray 140 which catchesmolten solder in the event that the bottom (or sides) of the solder bath106 is breached is also supported by the solder bath support 142. Alsoshown in FIG. 2 are the metal plates of the housing 102 which comprisethe housing 102, the overflow tray 104, face plate 128 of the housing102 as well as a connector PWB 524, a fuse 502, a fuse holder 504, atransformer 506, and a power switch 130 (discussed more fully below).

FIG. 3 illustrates in enlarged detail the heater assembly 144 of thepresent invention. The heater assembly 144 includes a first heatingblock 146 and a second heating block 148 with an opening 162 forinsertion of a first heater 150 and a second heater 152, respectively.The second heater 152 includes an integrated temperature sensor 170(shown in FIG. 10). The heating blocks 146 and 148 may be comprised ofcopper, a copper alloy or similar thermally conducting metal. On theother hand, the heaters 150 and 152 may be comprised of a ceramicinsulating resistance pattern of tungsten or a similar material whichwithstands very high temperatures. Alternatively, the heaters 150 and152 may be nickel-chrome or iron-chrome resistant wire heaters.Additionally, the heaters 150 and 152 are approximately four to eight mmin diameter, preferably six mm in diameter, and seventy to ninety mm inlength, preferably eighty mm in length. Generally, power consumption ofthe heaters 150 and 152 is between eighty and one-hundred and twentyWatts, typically one-hundred Watts. As shown in FIG. 3, the heatingblocks 146 and 148 are electrically coupled by lead wire 160 to aconnector 158, with insulating tubes 154 and 156 providing insulation onthe electrical terminals of heaters 150 and 152.

The soldering pot apparatus 100 is adapted to hold a plurality of sizesof the solder bath 106. For example, as shown in FIG. 4, a first solderbath 106 a may be exchanged for a second solder bath 106 b by rotatingscrews 120 (arrow 200) with the hex wrench 127. The first solder bath106 a may then be removed (arrow 202) and replaced with the secondsolder bath 106 b (arrow 204). The first solder bath 106 a may beapproximately fifty mm in length, fifty mm in width, and forty-two mm indepth, with a volume between ninety and one-hundred and twenty cm³,preferably one-hundred and five cm³. In contrast, the second solder bath106 b may be approximately seventy-five mm in length, seventy-five mm inwidth, and fifty-five mm in depth, with a volume between one-hundred andforty and one-hundred and seventy cm³, preferably one hundred and fiftyfive cm³. Alternatively, the first and second solder baths 106 a and 106b may be the same size. Both solder baths 106 a and 106 b may be made ofstainless steel, titanium, cast iron or similar heat-resistant material.Moreover, the solder bath 106 may be treated with an anti-erosiontreatment, such as enameling or a nitride coating. The method ofexchanging solder baths is explained below.

In FIG. 5, a simplified cross-sectional view of the soldering potapparatus of FIG. 1 is illustrated. In this embodiment, the firstheating block 146 and the second heating block 148 are shown inreleasable contact with the solder bath 106. The heating blocks 146 and148 may be situated equally opposite of one another adjacent to thesolder bath 106. The heating blocks 146 and 148 are held adjacent to thesolder bath 106 by the solder bath support 142 secured by screws 120,bolts 164 (see FIG. 6), a cam mechanism 166 (see FIG. 7) or a tighteningwheel mechanism 121 (see FIG. 8).

The solder bath support 142 includes at least two vertical legs 125 and127, at least two horizontal protrusions 123 and 129, at least two setsof flanges 133 and 135 and a lower horizontal member 131 adapted to beflush with a horizontal surface. As discussed previously, the horizontalprotrusions 123 and 129 support the bottom of the solder bath 106 suchthat it is held a distance above the lower horizontal member 131.Situated on the lower horizontal member 131 between the vertical legs125 and 127 of the solder bath support 142 may be the drip tray 140. Inthe event that molten solder compromises the structural integrity of thesolder bath 106, the tray 140 will catch any leaking molten solder andprotect the solder pot apparatus 100 from heat damage caused thereof.

FIGS. 6, 7 and 8 show alternative means to secure the heating blocks 146and 148 to the solder pot 106. In FIG. 6, bolts 164 may be used tosecure the horizontal member 131 of the solder bath support 142 to thebottom of the housing 102. The pressure on the solder bath support 142caused by tightening the bolts 164 to the bottom of the housing 102causes the heating blocks 146 and 148 to be flush with the solder bath106, thereby placing the heating blocks 146 and 148 in thermal contactwith the solder bath 106. In FIG. 7, cam mechanism 166, including a cam176, a connecting rod 174 and a handle 172 may be used to put theheating blocks 146 and 148 in thermal contact with solder bath 106.

In FIG. 8, a tightening wheel mechanism 121 is used to secure theheating blocks 146 and 148 to the solder bath 106. The housing 102 maybe modified such that it may accommodate the tightening wheel mechanism121, which includes an arm 137 and a wheel 135. In this embodiment, theneed for the solder bath support 142 is eliminated, as the tighteningwheel mechanism 121 provides sufficient support through pressure tosecure the solder bath 106 in a hanging position.

The mechanism used to secure the heating blocks 146 and 148 to thesolder bath 106 as previously described has several advantages. Forexample, because the heating blocks 146 and 148 are secured to thesolder bath 106 by pressure from the combination of the solder bathsupport 142 and securing means (such as screws 120, bolts 164, cammechanism 166 or a tightening wheel mechanism 121), the heating blocks146 and 148 may be easily mounted and dismounted from the solder bath106, facilitating ease of exchange of the solder bath 106 when necessary(see FIG. 4). Additionally, the securing mechanism as previouslydiscussed eliminates the need to secure a heating apparatus directlyonto or into the solder bath 106, which avoids the problem of a heatingapparatus sticking to the solder bath 106 due to high temperature,oxidation or molten solder drippings, making it difficult to exchangeeither the heating blocks or the solder bath.

FIGS. 9 a and 9 b illustrate the releasable capabilities of the heatingblocks 146 and 148 to the solder bath 106 in a cross-sectional view ofthe soldering pot apparatus 100. For example, in FIG. 9 a, the heatingblocks 146 and 148 are shown at a distance 171 away from the solder bath106 b after the solder bath 106 a has been exchanged for a second solderbath 106 b (see FIG. 4). In FIG. 9 b, the heating blocks 146 and 148 areshown in thermal contact with the solder bath 106 b caused by pressure(arrow 206) from tightening a securing means, such as screws 120.

FIG. 10 shows an electrical wiring diagram of the soldering potapparatus 100. The user interface is situated on a face plate 128 and isrepresented by the plurality of programmable buttons 132. Alternatively,a dial, pre-programmed buttons, switches or the like may be used as theuser interface. Through the programmable buttons 132, a user may programa time value, a solder type and/or a solder bath size (explained morefully below). The programmable buttons 132 are electrically coupled to aconnector PWB 524 by connector leads 532. Heater leads 534 originatingfrom the connector PWB 524 at a port 528 electrically couple to theheaters 150 and 152 of the heater assembly 144 supplying power thereto.Also, sensor leads 536 originating from the connector PWB 524 at theport 528 electrically couple to the sensor 170 of the heater 152 sensingresistance therefrom. At another port 530, electrically wiring 538electrically couple to a transformer 506, an ON/OFF switch 130, a fuseholder 504, and, finally, the power cord 122.

FIG. 11 is a block-type diagram of the schematics of the soldering potapparatus, and is to be read in conjunction with FIG. 10. In thisdiagram, the control PWB 525 (behind the face plate 128 as shown in FIG.2) is illustrated with circuitry, a microprocessor CPU 512 and aconnector 510. As shown, power is supplied to the heaters 150 and 152via an AC power input 500. The power is regulated by a plurality ofelectrical components, including a fuse 502, a power switch 130 and atransformer 506. The transformer 506 transforms commercial power fromthe AC power input 500 to approximately five volts of AC power. Oncepower passes through the transformer 506 via the connector 510, thepower passes through a low voltage power supply circuit 518. The powersupply circuit 518 prepares approximately five volts of DC power to besupplied to a microprocessor CPU 512. The CPU 512 calculates anddetermines certain processes according to both pre-installed softwareand user programmed parameters, which include a temperature controlfunction, a calibration function and start-up control according to theprogrammed solder type and programmed time value. The CPU 512 thensupplies power to the heaters 150 and 152 via a TRIAC 508. The TRIAC 508is an ON/OFF control of AC current to the heaters 150 and 152 inaccordance with signals from the CPU 512. The CPU 512 controls a powersupply in a two step process. First the CPU 512 compares an amplifiedsensor signal with the pre-determined value based on each solder typeduring the first start-up step. Next, the CPU 512 compares the signalwith the pre-set value based on the targeted temperature. Furthermore,the CPU 512 may use the PID control.

The sensor 170 may be comprised of ceramic insulating platinum ortungsten or other heat-resistant material and is incorporated within,for example, the heater 152. Moreover, the sensor 170 has thecharacteristic that its resistance value changes depending ontemperature, whereby the temperature is measured from the voltage causedby the sensor's resistance. The voltage caused by the resistance of thesensor 170 is amplified by a sensor signal amplifier circuit 516, whichpasses to the CPU 512. Also shown electrically coupled to the CPU 512 isa memory circuit 514, which stores certain pre-set parameters and anaccumulated used time (of the solder bath 106); an alarm buzzer circuit,which causes the CPU 512 to emit a sound once the accumulated used timeis reached; and, an LED display/user-programmable inputting circuit,which processes the user-programmed input via the plurality ofprogrammable buttons 132 displays digital information on the display134. Certain of the functions discussed are similar to those discussedin U.S. Pat. No. 4,891,497 by Yoshimura, whose entire contents arehereby incorporated by reference.

A feature of the present invention is a timing control mechanism whichmay be used to alert the user when to exchange the solder bath 106before it is breached by erosion. A user may program the timing controlmechanism by programming the programmable buttons 132 on the face plate128 to a preferred time value. Once the preferred time value is reached,the user is alerted by an alarm sound (and/or a visual signal), such asa buzzer, and the power supply to the heaters 150 and 152 ceases. Thepreferred time value chosen by the user will be retained even if thesoldering pot apparatus 100 is switched OFF or the power supply cord 122is pulled out from its socket. Advantageously, the timing controlmechanism 300 alerts the user to exchange the solder bath 106 with areplacement soldering bath before it begins to leak by erosion andcompromises the structural integrity and other components of thesoldering pot apparatus 100 by leaking molten solder. It should beappreciated that the timing control mechanism is not limited to theapplication discussed previously, but may be used for otherapplications, such as for programming a time value such that the solderpot apparatus 100 will automatically shut down at the end of a user'swork day.

The embodiment of the present invention as previously described may alsoinclude a temperature control mechanism. The user interface for thetemperature control mechanism generally includes a plurality of buttons132 on the face plate 128 of the housing 102. The plurality of buttons132 may be programmed with a numerical value which corresponds to aspecific solder type or to a solder bath size. For example, “21” maycorrespond to tin-lead, “22” may correspond to tin-silver-copper, “23”may correspond to tin-copper and “24” may correspond to tin. Similarly,“31” may correspond to a small solder bath 106 a, while “32” maycorrespond to a large solder bath 106 b. The numerical values programmedby the user ultimately correspond to a target temperature sufficient tosustain the molten state of conventional solders such as tin-lead,tin-silver-copper, tin-copper or tin. When a user programs the pluralityof buttons 132, full power is supplied to the heater assembly 144 of thesoldering pot apparatus 100 to liquefy the corresponding solder in thesolder bath 106 until the target temperature is reached. When comparedto conventional heating methods in electrical soldering baths, the timeto reach the pre-set target temperature of a given lead-based orlead-free solder is therefore decreased significantly, as illustrated bycomparing the graphs in FIGS. 12 and 13.

In the graph 300 of FIG. 12, the time to reach the target temperature inminutes for each of lead-free solders tin-silver-copper, tin-copper, andtin, in addition to lead-based solder tin-lead, is shown usingconventional temperature control methods. The target temperature wasreached at nineteen minutes and forty-seven seconds, fourteen minutesand thirty-six seconds, twenty-four minutes and forty-four seconds, fortin-silver-copper solder, tin-copper solder, and tin solder,respectively.

In contrast, in the graph 400 of FIG. 13, the time to reach the targettemperature in minutes for each of lead-free solders tin-silver-copper,tin-copper, and tin, in addition to lead-based solder tin-lead, is shownusing the temperature controlling mechanism of an embodiment of thepresent invention. The target temperature was reached at twelve minutesand ten seconds, nine minutes and forty-five seconds, and ten minutesand forty-four seconds, for tin-silver copper solder, tin-copper solder,and tin solder, respectively.

Thus, as illustrated, the temperature control mechanism significantlydecreases the time needed to liquefy a given lead-free solder. This, inturn, decreases the downtime experienced by a user when waiting for agiven solder to become molten, and also the power required. Moreover,once the target temperature is reached, the sensor prevents the heatingmechanism from further increasing or decreasing in temperature so thatthe solder does not overheat or become solid.

From the foregoing detailed description, it will be evident that thereare a number of changes, adaptations and modifications of the presentinvention which come within the province of those skilled in the art.The scope of the invention includes any combination of the elements fromthe different species or embodiments disclosed herein, as well assubassemblies, assemblies, and methods thereof. However, it is intendedthat all such variations not departing from the spirit of the inventionbe considered as within the scope thereof.

1. A soldering pot apparatus, comprising: a replaceable solder bath formolten solder; a support structure for supporting or hanging the solderbath in a solder heating position; and a heating unit movable relativeto the solder bath between a heating position in thermal transfercontact against the solder bath for heating solder in the solder bathand a removal position relative to the solder bath for allowing thesolder bath to be removed from the solder heating position.
 2. Theapparatus of claim 1, wherein the heating unit defines a first heatingunit, and further comprising a second heating unit movable between aheating position in thermal transfer contact against the solder bath forheating solder in the solder bath and a removal position relative to thesolder bath for allowing the solder bath to be removed from the heatingposition.
 3. The apparatus of claim 2, wherein the first and secondheating units are positioned on opposite sides of the solder bath whenin the solder heating positions, and the movement of the first andsecond heating units from their respective heating units to theirrespective removal positions are horizontal outward movements.
 4. Theapparatus of claim 1 wherein screw means moves the heating unit from theremoval position to the heating position.
 5. The apparatus of claim 1,wherein handle-operated camming means moves the heating unit.
 6. Asoldering pot apparatus, comprising: a replaceable solder bath formolten solder; support means for supporting or hanging the solder bathin a heating position; at least one heating unit; and moving means formoving the heating unit relative to the solder bath from a heatingposition in thermal contact with the solder bath to a removing positionallowing the solder bath to be removed from the heating position.
 7. Theapparatus of claim 6, wherein the moving means includes a plurality ofscrews.
 8. The apparatus of claim 6, wherein the moving means includes aplurality of bolts.
 9. The apparatus of claim 6, wherein the movingmeans includes a handle-operated camming assembly.
 10. The apparatus ofclaim 6, wherein the moving means includes turning wheel actuatedscrews.
 11. A soldering pot apparatus, comprising: a solder bath formolten solder; a heater assembly adapted to heat the solder bath; and apower control system adapted to control delivery of power to the heaterassembly and thereby heat to the solder bath, the power control systemincluding a user interface for indicating which of a plurality ofpre-selected solder types is to be melted in the solder bath, the powercontrol system applying full power to the heater assembly until apre-selected temperature over each melting point of the solder typeselected by a user via the user interface is attained.
 12. The apparatusof claim 11, further comprising a housing for supporting or hanging thesolder bath.
 13. The apparatus of claim 11, wherein the user interfaceincludes button means for inputting the pre-selected solder type to bemelted, the button means being supported by the housing.
 14. Theapparatus of claim 11, wherein the user interface includes a dialsupported by the housing, the dial having different positions forinputting the pre-selected solder type to be melted.
 15. The apparatusof claim 11, wherein the user interface includes switch means supportedby the housing for inputting the pre-selected solder type to be melted.16. A soldering pot apparatus, comprising: a housing; a heater assemblyfor heating a solder bath supported by the housing; and signal means forsignaling when the total anticipated time the solder bath has been usedreaches a predetermined time corresponding to an anticipated workablelife of a solder bath of the same type, whereby the solder bath can bereplaced.
 17. The apparatus of claim 16, further comprising a tray inthe housing, positioned below the solder bath and adapted to receive andhold solder leaking from the solder bath.
 18. A soldering pot apparatus,comprising: a solder bath for molten solder; and a heater circuit forheating the solder bath, the heater circuit including heating means forheating the solder bath, user input means for inputting which of aplurality of pre-selected solder types is to be heated in the solderbath, and control means for applying full power of the heating means tothe solder bath for a period of time corresponding to the solder typeinput by a user via the input means.
 19. The apparatus of claim 18,further comprising a tray positioned below the solder bath and adaptedto receive and hold solder leaking from the solder bath.
 20. A solderingpot heater assembly, comprising: a first heating block for a solderbath; a second heating block for the solder bath; a first heater coupledto the first heating block; a second heater coupled to the secondheating block; and a connector to which the first and second heaters areconnected.
 21. The heater assembly of claim 20, wherein the first heaterincludes a temperature sensor.
 22. The heater assembly of claim 20,wherein the first and second heaters are ceramic heaters.
 23. The heaterassembly of claim 20, wherein the first and second heating blocks arecopper or a copper alloy.
 24. A soldering pot apparatus, comprising: asolder bath for molten solder; a heater assembly for heating the solderbath; and user programmable means for controlling the operation of theheater assembly.
 25. The apparatus of claim 24 wherein the userprogrammable means includes at least one of (a) first selector meansallowing the user to indicate the size of the solder bath from aplurality of predetermined sizes and (b) second selector means forallowing the user to indicate the type of solder from a plurality ofpredetermined solder types.
 26. The apparatus of claim 25, wherein theuser programmable means controls the operation of the heater assemblybased on at least one of the indicated solder bath size and theindicated solder type.
 27. The apparatus of claim 25, wherein the userprogrammable means has the heater assembly operate at full power for aperiod of time determined by the user programmable means based on atleast one of the indicated solder bath size and solder type.
 28. Theapparatus of claim 24, wherein the user programmable means includestiming means for setting a signal timer.
 29. The apparatus of claim 24,further comprising a tray positioned below the solder bath and adaptedto receive and hold solder leaking from the solder bath.
 30. A methodfor operating a soldering pot apparatus, comprising: removing a firstsolder bath from a solder bath area of a soldering pot apparatus andfrom operative thermal contact with a heating assembly in a housing ofthe soldering pot assembly; and after the removing, positioning a secondsolder bath in the solder bath area and in operative thermal contactwith the heating assembly.
 31. The method of claim 30, wherein thepositioning includes moving the heating assembly into operative thermalcontact with the second solder bath in the solder bath area.
 32. Themethod of claim 31, wherein the moving includes pressing the heaterassembly into the contact by screwing at least one screw against theheater assembly.
 33. The method of claim 31, wherein the moving includespressing the heater assembly into the contact by operating ahandle-operated cam.
 34. The method of claim 31, wherein the movingmeans includes pressing the heater assembly in thermal contact byturning at least one turning wheel.
 35. The method of claim 31, whereinthe heater assembly includes first and second heater blocks, and themoving includes pressing the heater blocks against different sides ofthe second solder bath.
 36. The method of claim 30, wherein the firstsolder bath is approximately 105 cm³ and the second solder bath isapproximately 175 cm³.
 37. A method of heating solder, comprising:entering into a user input device of a soldering pot assemblyprogramming information to thereby establish at least in part a heatingregimen for a solder bath of the soldering pot assembly, the informationincluding a type of solder from a predetermined set of different soldertypes; and causing the soldering pot assembly to start the heatingregimen.
 38. The method of claim 37, wherein the information furtherincludes a solder bath size from predetermined sizes.
 39. The method ofclaim 37, wherein the entering includes actuating at least one actuator.40. The method of claim 39, wherein the at least one actuator is atleast one button.
 41. A soldering pot apparatus, comprising: a solderbath; a first heating block adjacent to one side of the solder bath; asecond heating block adjacent to one side of the solder bath andoppositely situated from the first heating block; a support toreleasably support the first and second heating blocks adjacent to thesolder bath; and securing means for securing the first heating block andthe second heating block to the solder bath.
 42. The apparatus claim of41, further comprising a housing and a solder drip collection traypositioned beneath the solder bath and in the housing.
 43. The apparatusof claim 42, wherein the housing at least substantially encloses thesolder bath, the first heating block, the second heating block, theheating block support and the tray.
 44. The apparatus of claim 41,wherein the solder bath is approximately cubical.
 45. The apparatus ofclaim 41, wherein the solder bath has a volume of between 90 and 170cm³.
 46. The apparatus of claim 41, wherein the support is approximatelyunshaped.
 47. The apparatus of claim 41, wherein the apparatus includesa timing control mechanism.
 48. The apparatus of claim 47, wherein thetiming control mechanism includes programming means, a heatingmechanism, a temperature sensor operatively connected to the heatingmechanism and an alarm.
 49. The apparatus of claim 47, wherein thetiming control mechanism is adapted to alert the user after apredetermined use time to change the solder bath to prevent solderleaking by erosion.
 50. The apparatus of claim 42, wherein the housingincludes a plurality of programmable buttons to program a solder type, asolder bath type, and a time value.
 51. The apparatus of claim 50,wherein the housing includes a display to display the solder type, thesolder bath type, the time value and a temperature.
 52. The apparatus ofclaim 41, wherein the securing means includes a plurality of screws. 53.The apparatus of claim 41, wherein the securing means includes a cammechanism.
 54. The apparatus of claim 41, wherein the securing meansincludes a plurality of bolts.
 55. The apparatus of claim 41, whereinthe securing means includes at least one screw and at least one turningwheel.
 56. A soldering pot apparatus, comprising: a solder bath; aheater assembly for heating the solder bath; means for securing theheater assembly to the solder bath; a solder bath support which supportsthe solder bath and the heater assembly; a housing which supports thesolder bath; and user programmable means for controlling the operationof the heater assembly, the programmable means being electricallycoupled to the heater assembly.
 57. The apparatus of claim 56, whereinthe heater assembly includes: a first heating block; a second heatingblock; a first ceramic heater including a temperature sensor and aninsulating tube, the first ceramic heater coupled to the first heatingblock; a second ceramic heater including an insulating tube, the secondceramic heater coupled to the second heating block; and a connector,wherein the first and second ceramic heaters are electrically coupled tothe connector by lead wires.
 58. The apparatus of 57, wherein the heaterassembly is releasably coupled to at least two surfaces of the solderbath.
 59. The apparatus of claim 57, wherein the first and secondheating blocks are comprised of a copper or a copper alloy.
 60. Theapparatus of claim 56, further comprising a solder drip collection traypositioned beneath the solder bath.
 61. The apparatus of claim 60,wherein the housing substantially houses the solder bath, the heaterassembly, the solder bath support and the collection tray.
 62. Theapparatus of claim 56, wherein the solder bath is between approximately90 and 170 cm³ in volume.
 63. The apparatus of claim 56, wherein thesolder bath is comprised of stainless steel, cast iron or titanium. 64.The apparatus of claim 56, wherein the solder bath support isapproximately u-shaped.
 65. The apparatus of claim 56, wherein theprogrammable means includes a plurality of buttons on the housing. 66.The apparatus of claim 65, wherein the plurality of buttons allows auser to input a solder type input by a user.
 67. The apparatus of claim65, wherein the plurality of buttons allows a user to input a solderbath size input by a user.
 68. The apparatus of claim 65, wherein theplurality of buttons allows a user to input a time value input by auser.
 69. The apparatus of claim 56, wherein the housing includes adisplay to display parameters corresponding to the solder type, thesolder bath type, the time value and a temperature.
 70. The apparatus ofclaim 56, wherein the securing means includes a plurality of screws orbolts.
 71. The apparatus of claim 56, wherein the securing meansincludes a cam mechanism.
 72. The apparatus of claim 56, wherein thesecuring means includes screws and at least one turning wheel for movingthe screws.
 73. A soldering pot apparatus, comprising: a solder bath; aheater assembly coupled to the solder bath; a housing at leastsubstantially enclosing the heater assembly and supporting the solderbath; and a circuit for storing an accumulated used time of the solderbath and pre-set parameters relating to temperature, timing, soldertype, and solder bath type, the circuit electrically coupled to theheater assembly.
 74. The apparatus of claim 73, wherein the heaterassembly includes: a first heating block; a second heating block; afirst ceramic heater including a temperature sensor and an insulatingtube, the first ceramic heater coupled to the first heating block; asecond ceramic heater including an insulating tube, the second ceramicheater coupled to the second heating block; and a connector, wherein thefirst and second ceramic heaters are electrically coupled to theconnector by lead wires.
 75. The apparatus of claim 73, wherein thecircuit includes timing control means for signaling the lapsing of aworking time value corresponding to an estimated lifetime of the solderbath.
 76. The apparatus of claim 73, wherein the circuit includestemperature control means for controlling heating rates applied to thesolder bath by the heater assembly.
 77. A method of alerting a user whento exchange a solder bath in an electrically-controlled soldering potapparatus, comprising: providing a solder bath housed in anelectrically-controlled soldering pot apparatus; providing a heaterassembly releasably coupled to the solder bath, the heater assemblyelectrically coupled to a programming mechanism; and programming theprogramming mechanism to set a desired time, wherein the power to theheater assembly is automatically cut off when the time is reached. 78.The method of claim 77, further comprising exchanging the solder bathwith a replacement solder bath after the time has been reached.
 79. Amethod of varying the heat intensity applied to at least one solder in asolder bath housed in an electrically-controlled soldering potapparatus, the method comprising: providing a solder bath housed in anelectrically-controlled soldering pot apparatus; providing a heaterassembly releasably coupled to the solder bath, the heater assemblyelectrically coupled to a programming mechanism; causing the mechanismto select a type of solder in the solder bath from a plurality ofpredetermined solder types; causing the mechanism to select a solderbath size from a plurality of predetermined solder bath sizes; actuatinga temperature start-up control to apply full power heat to the solderbath for a period of time determined from the selected solder type andthe selected solder bath size; causing the full power heat to cease oncea target temperature is reached; and controlling the temperature tomaintain solder in the solder bath in a molten state.
 80. The method ofclaim 79, wherein the solder is lead-free.
 81. The method of claim 79,wherein the solder is one of tin, tin-silver, tin-silver-copper andtin-copper.
 82. A method of exchanging a solder bath in anelectrically-controlled soldering pot apparatus, wherein the solder bathis releasably coupled to a heater assembly by holding means, comprising:releasing the holding means; removing a first solder bath from theapparatus; replacing the first solder bath with a second solder bath;and tightening the holding means.
 83. The method of claim 82, whereinthe holding means include screws, and the releasing includes unscrewingthe screws.
 84. The method of claim 82, wherein the holding meansincludes a cam mechanism, and the releasing includes moving a handle ofthe cam mechanism.
 85. The method of claim 82, wherein the holding meansincludes a turning wheel mechanism, and the releasing includes turning awheel of the turning wheel mechanism.